Patent Document 1 discloses an available travel distance display device for calculating the travelable distance of a vehicle based on a hypothetical amount-of-fuel value determined by subtracting a consumed amount of fuel and displaying the calculated travelable distance, the available travel distance display device including a travelable distance display device for gradually correcting the hypothetical amount-of-fuel value to approach an estimated amount-of-fuel value determined on the basis of the output of a reserve sensor when the available amount of fuel becomes equal to or lower than a reserve point (point E).
Also, Patent Document 2 discloses a display device for displaying the available travel distance of a vehicle by multiplying a reference mileage rate based on an interval mileage rate by the available amount of fuel when the available amount of fuel becomes equal to or lower than a reserve point (point E).